The road builders

Gerelateerde afbeelding

Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrane. In the rock itself are the essential clues to the scenes in which the rock began to form-a lake in Wyoming, about as large as Huron; a shallow ocean reaching westward from Washington Crossing; big rivers that rose in Nevada and fell through California to zakelijke energie the sea. Unfortunately, highway departments tend to obscure such scenes. They scatter seed wherever they think it will grow. They “hair everything over” -as geologists around the country will typically complain. “We think rocks are beautiful. Highway departments think rocks are obscene.” “In the North it’s vetch.” “In the South it’s the god-damned kudzu. You need a howitzer to blast through it. It covers the mountainsides, too.” “Almost all our stops on field trips are at roadcuts. In areas where structure is not well exposed, roadcuts are essential to do geology.” “Without some roadcuts, all you could do is drill a hole, or find natural streamcuts, which are few and far between.”
“We as geologists are fortunate to live in a period of great road building.” “It’s a way of sampling fresh rock. The road builders slice through indiscriminately, and no little rocks, no softer units are allowed to hide.” “A roadcut is to a geologist as a stethoscope is to a doctor.” “An X-ray to a dentist.” “The Rosetta Stone to an Egyptologist.” “A twenty-dollar bill to a hungry man.” “If I’m going to drive safely, I can’t do geology.” In moist climates, where vegetation veils the earth, streamcuts are about the only natural places where geologists can see exposures of rock, and geologists have walked hundreds of thousands of miles in and beside streams. If roadcuts in the moist world zakelijke energie vergelijken are a kind of gift, they are equally so in other places. Rocks are not easy to read where natural outcrops are so deeply weathered that a hammer will virtually sink out of sight-for example, in piedmont Georgia. Make a fresh roadcut almost anywhere at all and geologists will close in swiftly, like missionaries racing anthropologists to a tribe just discovered up the Xingu.